In such products as precision electronics, processed foods, medicinal drugs etc. which should be kept from high temperatures, strict temperature management is required so as for them not to experience a temperature history in which they are exposed to a temperature higher than a specified temperature, during production processes, storage periods and transportation. For example, temperature management members which are used by attaching them to the products and which have a temperature-sensitive discoloration layer that contains a granular or powdery hot-melt matter having a melting point which is a temperature to be detected and that discolors when the hot-melt matter is melted, are described in, for example, Patent Document 1 and Patent Document 2 below.
In addition, in Patent Document 3, a white-turbid-state opaque material at a room temperature, which is a mixture of a binder and a solid state powder-like chemical material such as a wax which becomes transparent when melted at a predetermined temperature, is screen-printed in a desired pattern on a semiconductor wafer. Then the wafer is inserted into a vacuum chamber and is heat-treated under a reduced pressure, thus measuring a heating distribution on the semiconductor wafer in the vacuum chamber.